Chapter 3.
DDL Script
Page 83

CREATE TABLE mc_patients 
(id NUMBER(9) 		NOT NULL
,ptype VARCHAR2(10) 		NOT NULL 
  CONSTRAINT mc_pat_cc1 CHECK (ptype IN ('INPATIENT'
                                       ,'OUTPATIENT'))
,surname VARCHAR2(30)		NOT NULL
,forename VARCHAR2(30) 		NOT NULL
,date_of_birth DATE
,f_bal_bed NUMBER(9)
,CONSTRAINT mc_pat_pk PRIMARY KEY (id)
,CONSTRAINT mc_pat_bal_fk FOREIGN KEY
  REFERENCES mc_bed_allocations
,CONSTRAINT mc_pat_cc2 CHECK(ptype = 'INPATIENT' OR
                             f_bal_bed IS NULL));

CREATE VIEW mc_outpatients_v AS
SELECT pat.id
      ,pat.surname
      ,pat.forename
      ,date_of_birth
FROM   mc_patients pat
WHERE  pat.ptype = 'OUTPATIENT'
WITH CHECK OPTION CONSTRAINT mc_opt_cc1;

CREATE VIEW mc_inpatients_v  ...